Effects of ginger and cranberry
This study hypothesized that ginger (Zingiber officinale) and cranberry (Vaccinium macrocarpon) extracts would alter the physiological response to exercise as well as markers of muscle damage, and mRNA expression for the inflammatory cytokines tumour necrosis factor-a (TNF-a), interferon-g (IFN-g) and interleukin-6 (IL-6) after an exhaustive bout of exercise in horses. Nine unfit Standardbred mares (age 10 ^ 4 years, ,450 kg) completed three graded exercise tests (GXTs) in a crossover design, where they were assigned to the initial order of treatment in a randomized fashion. The GXTs were conducted between 07.00 and 12.00 hours, 7 days apart. Mares received either water (2 l), cranberry (,30 g in 2 l of water) or ginger (,30 g in 2 l of water) extract 1 h prior to testing. Blood samples were taken prior to dosing (pre-exercise), at the end of each step of the GXT, at the end of the exercise and at 2, 5 and 30 min, 1, 2, 4 and 24 h post-GXT. Plasma total protein (TP) concentration and haematocrit (HCT) were analysed immediately following the tests. Analysis of creatine kinase (CK) and aspartate aminotransferase (AST) was done commercially. There was no effect of treatment (P > 0.05) on VO2max, run-time to fatigue, core temperature, TP or HCT. CK was substantially elevated (P 0.05) was noted in AST. A slight increase (P 0.05) was seen on IL-6 mRNA expression. Results suggest that cranberry extract blunts the upregulation and expression of TNF-a mRNA, while ginger extract reduces cardiovascular recovery time in horses completing a short, exhaustive bout of exercise.